Temporal stratification of weeds under System of Rice Intensification and conventional rice cultivation

A synecological studyon weeds was conducted to observe their temporal stratification and diversity in rice fields. The survey was performed across thephenophasesof rice (vegetative phase, reproductive phase, and mature phase.) to understand the crop-weed interaction. In this study, two cultural practices of rice cultivation, conventional and System of Rice Intensification (SRI) were considered. The weeds collected from the field were identified, and biomass, relative abundances were calculated. Also, diversity indices such as Simpson’s Index, Shannon index andevennesswere computed. The ecosystem service generated from the weeds were documented.The study showed that the conventional plots were more diverse than the SRI plots. However, higher biomass for weed species was observed under SRI when compared to conventional plots. There were 24 dicotyledonous and 18 monocotyledonous weed species. From the abundance study,it was found that the SRI plots were more evenover the conventional plots. Thus, nutrient competition and sharing between the rice plants and weeds differ temporallyin SRI and conventional plots.The study suggests selective removal of weeds from the rice fields that will improve the crop yield as well as generate various ecosystem services.